JP5725151B2 - Silicon-containing film forming composition for multilayer resist process and pattern forming method - Google Patents

Description

  The present invention relates to a silicon-containing film forming composition for a multilayer resist process and a pattern forming method using the same.

  Conventionally, in a manufacturing process of a semiconductor device such as an IC or LSI, fine processing by lithography using a photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Along with this, there is a tendency to shorten the exposure wavelength from g-line to i-line, KrF excimer laser light, and further ArF excimer laser light. For example, the immersion exposure method, which is a miniaturization technique using ArF excimer laser light, enables miniaturization of 50 nm or less (see Patent Document 1). However, it is expected that further miniaturization technology of 30 nm or less will be required in the future.

  As miniaturization technology after ArF excimer laser light, in addition to lithography using electron beams, X-rays, etc., EUV lithography (hereinafter also referred to as “EUVL”) using extreme ultraviolet light with a wavelength of 13.5 nm or less as a light source has been studied. ing.

  By using EUVL, fine patterning of 20 nmhp (half pitch) is also possible. However, it is expected that it becomes difficult to obtain sufficient processability by the conventional single layer process (resist film + antireflection film + substrate) due to the thinning of the resist due to miniaturization.

International Publication No. 04/068242 Pamphlet

  The present invention has been made based on the circumstances as described above, and its purpose is to form a resist pattern that is excellent in pattern collapse resistance, resolution, and rectangularity of the pattern shape, and thus in processing performance in a multilayer resist process. It is to provide an excellent silicon-containing film forming composition for a multilayer resist process.

The invention made to solve the above problems is
A silicon-containing film-forming composition for a multilayer resist process, which contains [A] polysiloxane and [B] an electron acceptor.

  The silicon-containing film forming composition for a multilayer resist process of the present invention contains [B] an electron acceptor in addition to [A] polysiloxane, thereby resisting pattern collapse of a resist pattern formed on the silicon-containing film comprising the same. Further, the lithography performance such as the resolution and the rectangularity of the pattern shape can be improved. Moreover, the processing performance in a multilayer resist process can be improved through such an excellent resist pattern. [B] The electron acceptor has a role of accepting electrons generated by the role of radiation near the interface between the formed silicon-containing film and the resist film. This makes it possible to control the amount of electrons that contribute to the decomposition of the acid generator and the like in the resist composition in the vicinity of the interface between the silicon-containing film and the resist film. As a result, it is possible to control the shape of the bottom part of the resist pattern by suppressing the excessive deprotection reaction of the polymer having acid dissociable groups in the resist composition in the vicinity of the interface between the silicon-containing film and the resist film. Therefore, it is considered that lithography performance such as resistance to pattern collapse, resolution, and rectangularity of the pattern shape can be improved. In addition, it is considered that through the formation of a resist pattern having excellent performance, it is possible to improve the processing performance when performing dry etching of a silicon-containing film, a substrate or the like in a multilayer resist process using the composition. . Therefore, according to the silicon-containing film forming composition for a multilayer resist process, a good pattern can be formed by the multilayer resist process while exhibiting excellent processing performance.

  [B] The electron acceptor is at least one compound selected from the group consisting of quinone compounds, quinodimethane compounds, dibenzofuran compounds, and compounds represented by the following formulas (1-1) and (1-2). Is preferred.

（式（１−１）及び式（１−２）中、Ｒ^１〜Ｒ^５は、それぞれ独立して、水素原子、アルキル基、アルコキシ基、ヒドロキシル基又はハロゲン原子である。Ｚ⁻及びＱ⁻は、それぞれ独立して、ＯＨ⁻、Ｒ^Ａ−ＣＯＯ⁻、Ｒ^Ａ−ＳＯ_３ ⁻又はＲ^Ａ−Ｎ⁻−ＳＯ_２−Ｒ^Ｂである。Ｒ^Ａは、アルキル基、シクロアルキル基、アリール基又はアラルキル基である。但し、Ｒ^Ａが有する水素原子の一部又は全部は置換されていてもよい。Ｒ^Ｂは、アルキル基又はアラルキル基である。但し、Ｒ^Ｂが有する水素原子の一部又は全部はフッ素原子で置換されていてもよい。）

(In Formula (1-1) and Formula (1-2), R ^{1 to} R ⁵ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. Z ⁻ and Q ^−. are each ^{independently, OH -, R a -COO -} , R a -SO 3 - or ^R a ^-N - is .R ^a is _-SO 2 -R ^B, an alkyl group, a cycloalkyl group, an aryl group Or an aralkyl group, wherein a part or all of the hydrogen atoms that R ^A has may be substituted, and R ^B is an alkyl group or an aralkyl group, provided that a part of the hydrogen atoms that R ^B has. Alternatively, all may be substituted with fluorine atoms.)

  According to the silicon-containing film forming composition for a multilayer resist process, it is considered that the amount of electrons described above can be controlled more appropriately by using [B] the electron acceptor as the specific compound. As a result, it is possible to further improve the resistance to pattern collapse, the resolution, and the rectangularity of the pattern shape of the resist pattern to be formed, and the processing performance can be improved.

  [A] The polysiloxane is preferably a hydrolysis condensate of a compound containing a silane compound represented by the following formula (2) (hereinafter also referred to as “silane compound (2)”).

（式（２）中、Ｒ^６は、水素原子、フッ素原子、炭素数１〜５のアルキル基、シアノ基、シアノアルキル基、アルキルカルボニルオキシ基、アルケニル基、アリール基又はアラルキル基である。このアルキル基はフッ素原子で置換されていてもよく、アリール基及びアラルキル基は置換されていてもよい。Ｘは、ハロゲン原子又は−ＯＲ^７である。Ｒ^７は、１価の有機基である。ａは、０〜３の整数である。但し、Ｒ^６及びＸがそれぞれ複数の場合、複数のＲ^６及びＸはそれぞれ同一でも異なっていてもよい。）

(In formula (2), R ⁶ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, a cyano group, a cyanoalkyl group, an alkylcarbonyloxy group, an alkenyl group, an aryl group, or an aralkyl group. The alkyl group may be substituted with a fluorine atom, the aryl group and the aralkyl group may be substituted, X is a halogen atom or —OR ^7. R ⁷ is a monovalent organic group. a is 0-3 is an integer of. However, when a plurality of R ⁶ and X are each the plurality of R ⁶ and X may be the same as or different from each other.)

  According to the silicon-containing film forming composition for a multilayer resist process, by forming a silicon-containing film using the [A] polysiloxane having the specific structure, pattern collapse resistance, resolution, and resolution of the formed resist pattern can be improved. The rectangularity of the pattern shape can be further improved, and the processing performance can be further improved.

  Since the composition for forming a silicon-containing film for a multilayer resist process has the above-described properties, it can be suitably used for exposure to extreme ultraviolet rays, X-rays or electron beams.

The pattern forming method of the present invention (hereinafter also referred to as “pattern forming method I”)
(I-1) A step of forming a silicon-containing film on the upper surface side of a substrate to be processed using a silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane and [B] an electron acceptor,
(I-2) a step of forming a resist film on the silicon-containing film using a resist composition;
(I-3) a step of exposing the resist film by irradiation with radiation through a photomask;
(I-4) developing the exposed resist film to form a resist pattern, and (I-5) sequentially etching the silicon-containing film and the substrate to be processed using the resist pattern as a mask. Have.

  According to the pattern forming method I, since the silicon-containing film forming composition for a multilayer resist process described above is used, a resist pattern excellent in pattern collapse resistance, resolution, and rectangularity of the pattern shape can be formed. Thus, a good pattern can be formed on the substrate to be processed while exhibiting excellent processing performance.

  The radiation in the step (I-3) is preferably extreme ultraviolet rays, X-rays or electron beams. Since the pattern forming method I uses the silicon-containing film forming composition for a multilayer resist process having the above-described properties, the effect is more exhibited when using these radiations, and a better pattern can be formed.

Further, another pattern forming method of the present invention (hereinafter also referred to as “pattern forming method II”)
(II-1) A step of forming a silicon-containing film on the upper surface side of the substrate to be processed using the silicon-containing film-forming composition for a multilayer resist process containing [A] polysiloxane,
(II-2) forming a resist film on the silicon-containing film using a resist composition;
(II-3) a step of exposing the resist film by irradiation with extreme ultraviolet rays or an electron beam through a photomask;
(II-4) developing the exposed resist film to form a resist pattern, and (II-5) sequentially etching the silicon-containing film and the substrate to be processed using the resist pattern as a mask. Have.

  According to the pattern forming method II, [A] a silicon-containing film forming composition for a multilayer resist process containing polysiloxane, and using the specific radiation, the pattern collapse resistance and resolution can be achieved by the multilayer resist process. It is possible to form a resist pattern having excellent properties, and through this, a good pattern can be formed on the substrate to be processed while exhibiting excellent processing performance.

  Here, the “organic group” refers to a group containing at least one carbon atom.

  As described above, according to the silicon-containing film forming composition for multilayer resist process and the pattern forming method of the present invention, a resist pattern excellent in lithography performance such as pattern collapse resistance, resolution, and rectangularity of pattern shape is formed. In addition, through such an excellent resist pattern, it is possible to form a good pattern on the substrate to be processed while exhibiting excellent processing performance. Therefore, the present invention can be suitably used for a semiconductor device manufacturing process and the like that will be increasingly miniaturized in the future, and can also be suitably used particularly in a multilayer resist process in a region finer than 50 nm.

It is a schematic diagram of the resist pattern cross section formed by the multilayer resist process.

<Silicon-containing film forming composition for multilayer resist process>
The silicon-containing film forming composition for a multilayer resist process contains [A] polysiloxane and [B] electron acceptor. Moreover, the silicon-containing film forming composition for a multilayer resist process may contain a [C] solvent as a suitable component, and may contain other optional components as long as the effects of the present invention are not impaired. Also good. Hereinafter, each component will be described.

<[A] polysiloxane>
[A] The structure of the polysiloxane is not particularly limited, but is preferably a hydrolysis condensate of a compound containing the silane compound represented by the above formula (2). By using such [A] polysiloxane, it is possible to improve pattern collapse resistance, resolution, and pattern shape rectangularity of the resist pattern to be formed.

In the above formula (2), R ⁶ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, cyano group, cyanoalkyl group, alkylcarbonyloxy group, an alkenyl group, an aryl group or an aralkyl group. This alkyl group may be substituted with a fluorine atom, and the aryl group and the aralkyl group may be substituted. X is a halogen atom or —OR ⁷ . R ⁷ is a monovalent organic group. a is an integer of 0-3. However, in the case of multiple R ⁶ and X are each the plurality of R ⁶ and X may be the same as or different from each other.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ⁶ include linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group; Groups, branched alkyl groups such as isobutyl group, sec-butyl group, t-butyl group, isoamyl group, and the like.

Examples of the alkyl group having 1 to 5 carbon atoms substituted by the fluorine atom represented by R ⁶ include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a fluoroethyl group, a difluoroethyl group, and trifluoroethyl. Group, perfluoroethyl group, perfluoro n-propyl group, hexafluoro-i-propyl group, perfluorobutyl group and the like.
Examples of the cyanoalkyl group represented by R ⁶ include a cyanoethyl group and a cyanopropyl group.
Examples of the alkylcarbonyloxy group represented by R ⁶ include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group.

Examples of the alkenyl group represented by R ⁶ include a group represented by the following formula (i-1).
_{CH 2 = CH- (CH 2)} n - * (i-1)
In said formula (i-1), n is an integer of 0-4. * Indicates a bond.
N is preferably 0 or 1, more preferably 0 (vinyl group).

Examples of the aryl group represented by R ⁶ include a phenyl group, a naphthyl group, a methylphenyl group, and an ethylphenyl group.

Examples of the aralkyl group represented by R ⁶ include a benzyl group, a phenylethyl group, a phenylpropyl group, and a naphthylmethyl group.

  Examples of the substituent that the aryl group and the aralkyl group may have include, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxy group, An aryloxy group, an acyl group, an amino group, a substituted amino group, etc. are mentioned.

Examples of the halogen atom represented by X include a fluorine atom and a chlorine atom.
Examples of the monovalent organic group represented by R ⁷ in -OR ⁷ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. C1-C4 alkyl groups, such as a butyl group, etc. are mentioned.
As said a, the integer of 0-2 is preferable.

Specific examples of the silane compound (2) include, for example, phenyltrimethoxysilane, benzyltrimethoxysilane, phenethyltrimethoxysilane, 4-methylphenyltrimethoxysilane, 4-ethylphenyltrimethoxysilane, 4-methoxyphenyltrimethoxy. Silane, 4-phenoxyphenyltrimethoxysilane, 4-hydroxyphenyltrimethoxysilane, 4-aminophenyltrimethoxysilane, 4-dimethylaminophenyltrimethoxysilane, 4-acetylaminophenyltrimethoxysilane, 3-methylphenyltrimethoxy Silane, 3-ethylphenyltrimethoxysilane, 3-methoxyphenyltrimethoxysilane, 3-phenoxyphenyltrimethoxysilane, 3-hydroxyphenyltrimethoxysilane, 3-a Nophenyltrimethoxysilane, 3-dimethylaminophenyltrimethoxysilane, 3-acetylaminophenyltrimethoxysilane, 2-methylphenyltrimethoxysilane, 2-ethylphenyltrimethoxysilane, 2-methoxyphenyltrimethoxysilane, 2- Phenoxyphenyltrimethoxysilane, 2-hydroxyphenyltrimethoxysilane, 2-aminophenyltrimethoxysilane, 2-dimethylaminophenyltrimethoxysilane, 2-acetylaminophenyltrimethoxysilane, 2,4,6-trimethylphenyltrimethoxy Silane, 4-methylbenzyltrimethoxysilane, 4-ethylbenzyltrimethoxysilane, 4-methoxybenzyltrimethoxysilane, 4-phenoxybenzyltrimethoxysilane, 4-hydride Aromatic-containing trialkoxysilanes such as loxybenzyltrimethoxysilane, 4-aminobenzyltrimethoxysilane, 4-dimethylaminobenzyltrimethoxysilane, 4-acetylaminobenzyltrimethoxysilane;
Methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, Methyltriacetoxysilane, methyltrichlorosilane, methyltriisopropenoxysilane, methyltris (dimethylsiloxy) silane, methyltris (methoxyethoxy) silane, methyltris (methylethylketoxime) silane, methyltris (trimethylsiloxy) silane, methylsilane, ethyltrimethoxysilane Ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n- Toxisilane, ethyltri-sec-butoxysilane, ethyltri-tert-butoxysilane, ethyltriphenoxysilane, ethylbistris (trimethylsiloxy) silane, ethyldichlorosilane, ethyltriacetoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-sec-butoxysilane, n-propyl Tri-tert-butoxysilane, n-propyltriphenoxysilane, n-propyltriacetoxysilane, n-propyltrichlorosilane, iso-propyltrimethoxysilane, iso-propyltrie Xysilane, iso-propyltri-n-propoxysilane, iso-propyltri-iso-propoxysilane, iso-propyltri-n-butoxysilane, iso-propyltri-sec-butoxysilane, iso-propyltri-tert-butoxy Silane, iso-propyltriphenoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane, n-butyltri-sec-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, n-butyltrichlorosilane, 2-methylpropyltrimethoxysilane, 2-methylpropyltriethoxysilane Lan, 2-methylpropyltri-n-propoxysilane, 2-methylpropyltri-iso-propoxysilane, 2-methylpropyltri-n-butoxysilane, 2-methylpropyltri-sec-butoxysilane, 2-methylpropyl Tri-tert-butoxysilane, 2-methylpropyltriphenoxysilane, 1-methylpropyltrimethoxysilane, 1-methylpropyltriethoxysilane, 1-methylpropyltri-n-propoxysilane, 1-methylpropyltri-iso- Propoxysilane, 1-methylpropyltri-n-butoxysilane, 1-methylpropyltri-sec-butoxysilane, 1-methylpropyltri-tert-butoxysilane, 1-methylpropyltriphenoxysilane, tert-butyltrimethoxy Orchid, tert-butyltriethoxysilane, tert-butyltri-n-propoxysilane, tert-butyltri-iso-propoxysilane, tert-butyltri-n-butoxysilane, tert-butyltri-sec-butoxysilane, tert-butyltri-tert -Alkyltrialkoxysilanes such as butoxysilane, tert-butyltriphenoxysilane, tert-butyltrichlorosilane, tert-butyldichlorosilane;
Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltriisopropoxysilane, vinyltri-n-butoxysilane, vinyltri-sec-butoxysilane, vinyltri-tert-butoxysilane, vinyltriphenoxysilane, allyl Alkenyl such as trimethoxysilane, allyltriethoxysilane, allyltri-n-propoxysilane, allyltriisopropoxysilane, allyltri-n-butoxysilane, allyltri-sec-butoxysilane, allyltri-tert-butoxysilane, allyltriphenoxysilane Trialkoxysilanes;
Tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane; tetraphenoxy Silane, tetrachlorosilane, etc. are mentioned.

  Among these, phenyltrimethoxysilane, 4-methylphenyltrimethoxysilane, 4-methoxyphenyltrimethoxysilane, 4-methylbenzyltrimethoxysilane, methyltrimethoxysilane, methyl from the viewpoints of reactivity and ease of handling of substances. Trimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n -Propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n-butoxysilane, ethyltri-sec-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane N-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-sec-butoxysilane, vinyltrimethoxysilane, vinyltriethoxy Silane, allyltrimethoxysilane, and allyltriethoxysilane are preferable, and phenyltrimethoxysilane is more preferable.

  Further, from the viewpoint of obtaining a pattern excellent in dry etching resistance, tetramethoxysilane and tetraethoxysilane are preferable, and tetramethoxysilane is more preferable.

[A] As a silane compound for obtaining polysiloxane, in addition to the compound (2), other silane compounds may include hexamethoxydisilane, hexaethoxydisilane, hexaphenoxydisilane, 1,1,1 as necessary. , 2,2-pentamethoxy-2-methyldisilane, 1,1,1,2,2-pentaethoxy-2-methyldisilane, 1,1,1,2,2-pentaphenoxy-2-methyldisilane, 1,1,1,2,2-pentamethoxy-2-ethyldisilane, 1,1,1,2,2-pentaethoxy-2-ethyldisilane, 1,1,1,2,2-pentaphenoxy-2- Ethyldisilane, 1,1,1,2,2-pentamethoxy-2-phenyldisilane, 1,1,1,2,2-pentaethoxy-2-phenyldisilane, 1,1,1,2,2-pe Taphenoxy-2-phenyldisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, 1,1,2, 2-tetraphenoxy-1,2-dimethyldisilane, 1,1,2,2-tetramethoxy-1,2-diethyldisilane, 1,1,2,2-tetraethoxy-1,2-diethyldisilane, 1, 1,2,2-tetraphenoxy-1,2-diethyldisilane, 1,1,2,2-tetramethoxy-1,2-diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-diphenyl Disilane, 1,1,2,2-tetraphenoxy-1,2-diphenyldisilane, 1,1,2-trimethoxy-1,2,2-trimethyldisilane, 1,1,2-triethoxy-1,2,2 Trimethyldisilane, 1,1,2-triphenoxy-1,2,2-trimethyldisilane, 1,1,2-trimethoxy-1,2,2-triethyldisilane, 1,1,2-triethoxy-1,2, 2-triethyldisilane, 1,1,2-triphenoxy-1,2,2-triethyldisilane, 1,1,2-trimethoxy-1,2,2-triphenyldisilane, 1,1,2-triethoxy-1 , 2,2-triphenyldisilane, 1,1,2-triphenoxy-1,2,2-triphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2- Diethoxy-1,1,2,2-tetramethyldisilane, 1,2-diphenoxy-1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraethyldisi Lan, 1,2-diethoxy-1,1,2,2-tetraethyldisilane, 1,2-diphenoxy-1,1,2,2-tetraethyldisilane, 1,2-dimethoxy-1,1,2,2- Disilanes such as tetraphenyldisilane, 1,2-diethoxy-1,1,2,2-tetraphenyldisilane, 1,2-diphenoxy-1,1,2,2-tetraphenyldisilane;
Bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, bis (tri-n-propoxysilyl) methane, bis (tri-isopropoxysilyl) methane, bis (tri-n-butoxysilyl) methane, bis ( Tri-sec-butoxysilyl) methane, bis (tri-tert-butoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1,2-bis ( Tri-n-propoxysilyl) ethane, 1,2-bis (tri-isopropoxysilyl) ethane, 1,2-bis (tri-n-butoxysilyl) ethane, 1,2-bis (tri-sec-butoxysilyl) ) Ethane, 1,2-bis (tri-tert-butoxysilyl) ethane, 1- (dimethoxymethylsilyl) -1- (trimeth) Sisilyl) methane, 1- (diethoxymethylsilyl) -1- (triethoxysilyl) methane, 1- (di-n-propoxymethylsilyl) -1- (tri-n-propoxysilyl) methane, 1- (di -Isopropoxymethylsilyl) -1- (tri-isopropoxysilyl) methane, 1- (di-n-butoxymethylsilyl) -1- (tri-n-butoxysilyl) methane, 1- (di-sec-butoxy Methylsilyl) -1- (tri-sec-butoxysilyl) methane, 1- (di-tert-butoxymethylsilyl) -1- (tri-tert-butoxysilyl) methane, 1- (dimethoxymethylsilyl) -2- (Trimethoxysilyl) ethane, 1- (diethoxymethylsilyl) -2- (triethoxysilyl) ethane, 1- (di-n-propoxymethyl) Yl) -2- (tri-n-propoxysilyl) ethane, 1- (di-isopropoxymethylsilyl) -2- (tri-isopropoxysilyl) ethane, 1- (di-n-butoxymethylsilyl) -2 -(Tri-n-butoxysilyl) ethane, 1- (di-sec-butoxymethylsilyl) -2- (tri-sec-butoxysilyl) ethane, 1- (di-tert-butoxymethylsilyl) -2- ( Tri-tert-butoxysilyl) ethane,
Bis (dimethoxymethylsilyl) methane, bis (diethoxymethylsilyl) methane, bis (di-n-propoxymethylsilyl) methane, bis (di-isopropoxymethylsilyl) methane, bis (di-n-butoxymethylsilyl) Methane, bis (di-sec-butoxymethylsilyl) methane, bis (di-tert-butoxymethylsilyl) methane, 1,2-bis (dimethoxymethylsilyl) ethane, 1,2-bis (diethoxymethylsilyl) ethane 1,2-bis (di-n-propoxymethylsilyl) ethane, 1,2-bis (di-isopropoxymethylsilyl) ethane, 1,2-bis (di-n-butoxymethylsilyl) ethane, 1, 2-bis (di-sec-butoxymethylsilyl) ethane, 1,2-bis (di-tert-butoxymethylsilyl) Ethane, bis (dimethylmethoxysilyl) methane, bis (dimethylethoxysilyl) methane, bis (dimethyl-n-propoxysilyl) methane, bis (dimethyl-isopropoxysilyl) methane, bis (dimethyl-n-butoxysilyl) methane, Bis (dimethyl-sec-butoxysilyl) methane, bis (dimethyl-tert-butoxysilyl) methane, 1,2-bis (dimethylmethoxysilyl) ethane, 1,2-bis (dimethylethoxysilyl) ethane, 1,2- Bis (dimethyl-n-propoxysilyl) ethane, 1,2-bis (dimethyl-isopropoxysilyl) ethane, 1,2-bis (dimethyl-n-butoxysilyl) ethane, 1,2-bis (dimethyl-sec- Butoxysilyl) ethane, 1,2-bis (dimethyl-tert-but Shishiriru) ethane,
1- (dimethoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (diethoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (di-n-propoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (di-isopropoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (di-n-butoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (di-sec-butoxymethylsilyl) -1 -(Trimethylsilyl) methane, 1- (di-tert-butoxymethylsilyl) -1- (trimethylsilyl) methane, 1- (dimethoxymethylsilyl) -2- (trimethylsilyl) ethane, 1- (diethoxymethylsilyl) -2 -(Trimethylsilyl) ethane, 1- (di-n-propoxymethylsilyl) -2- ( Limethylsilyl) ethane, 1- (di-isopropoxymethylsilyl) -2- (trimethylsilyl) ethane, 1- (di-n-butoxymethylsilyl) -2- (trimethylsilyl) ethane, 1- (di-sec-butoxymethyl) Bissilyl group-containing silanes such as silyl) -2- (trimethylsilyl) ethane and 1- (di-tert-butoxymethylsilyl) -2- (trimethylsilyl) ethane;
1,2-bis (trimethoxysilyl) benzene, 1,2-bis (triethoxysilyl) benzene, 1,2-bis (tri-n-propoxysilyl) benzene, 1,2-bis (tri-isopropoxysilyl) ) Benzene, 1,2-bis (tri-n-butoxysilyl) benzene, 1,2-bis (tri-sec-butoxysilyl) benzene, 1,2-bis (tri-tert-butoxysilyl) benzene, 1, 3-bis (trimethoxysilyl) benzene, 1,3-bis (triethoxysilyl) benzene, 1,3-bis (tri-n-propoxysilyl) benzene, 1,3-bis (tri-isopropoxysilyl) benzene 1,3-bis (tri-n-butoxysilyl) benzene, 1,3-bis (tri-sec-butoxysilyl) benzene, 1,3-bis (tri tert-butoxysilyl) benzene, 1,4-bis (trimethoxysilyl) benzene, 1,4-bis (triethoxysilyl) benzene, 1,4-bis (tri-n-propoxysilyl) benzene, 1,4- Bis (tri-isopropoxysilyl) benzene, 1,4-bis (tri-n-butoxysilyl) benzene, 1,4-bis (tri-sec-butoxysilyl) benzene, 1,4-bis (tri-tert- Disilanes such as butoxysilyl) benzene;
Examples thereof include polycarbosilane such as polydimethoxymethylcarbosilane and polydiethoxymethylcarbosilane. These silane compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  [A] Only one type of polysiloxane may be contained in the silicon-containing film forming composition for a multilayer resist process, or two or more types may be contained.

  [A] The polystyrene-reduced weight average molecular weight (Mw) of the polysiloxane by gel permeation chromatography (GPC) is preferably 2,000 to 100,000, more preferably 2,000 to 50,000, and even more preferably 2. 3,000 to 30,000, particularly preferably 2,000 to 10,000.

  In addition, Mw of [A] polysiloxane in this specification uses a Tosoh GPC column ("G2000HXL", "G3000HXL", "G4000HXL"), flow rate: 1.0 mL / min , Elution solvent: tetrahydrofuran, column temperature: a value measured by GPC using monodisperse polystyrene as a standard under analysis conditions of 40 ° C.

  As a method for hydrolyzing and condensing the silane compound (2) and other silane compounds used as necessary, a known hydrolytic condensation method can be used.

  [A] The content of polysiloxane is usually 70% by mass or more, preferably 80% by mass or more, and preferably 90% by mass or more based on the total solid content of the silicon-containing film forming composition for multilayer resist process. Further preferred.

<[B] electron acceptor>
[B] An electron acceptor is a substance having a function of accepting electrons. [B] The electron acceptor is not particularly limited as long as it has the above properties. [B] The inclusion form of the electron acceptor may be a compound form as described later, for example, [A] a polysiloxane or other polymer having a group having a function of accepting electrons, or both. It may be a form. [B] Electron acceptors are generated near the interface between the silicon-containing film and the resist film by irradiation with various types of radiation such as extreme ultraviolet rays such as EUV, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. It has a role of accepting electrons. This makes it possible to control the amount of electrons contributing to the decomposition of an acid generator (P) or the like in the resist composition described later in the vicinity of the interface between the silicon-containing film and the resist film. As a result, it is possible to control the shape of the bottom part of the resist pattern by suppressing the excessive deprotection reaction of the polymer having acid dissociable groups in the resist composition in the vicinity of the interface between the silicon-containing film and the resist film. Therefore, it is considered that lithography performance such as resistance to pattern collapse, resolution, and rectangularity of the pattern shape can be improved.

  [B] The electron acceptor is at least one compound selected from the group consisting of a quinone compound, a quinodimethane compound, a dibenzofuran compound, and compounds represented by the above formulas (1-1) and (1-2). It is preferable.

  Examples of the quinone compound, the quinodimethane compound, and the dibenzofuran compound include compounds represented by the following formula (3-1) to the following formula (3-5).

In said formula (3-1)-(3-5), Y is respectively independently a hydrogen atom, a hydroxyl group, a halogen atom, or a cyano group. R ^X0 is independently a hydrogen atom, a hydroxyl group, a carboxyl group, a halogen atom or a cyano group. However, at least one R ^X0 in the compound is a cyano group.

  Examples of the halogen atom represented by Y include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Y is preferably a halogen atom or a cyano group, more preferably a fluorine atom, a chlorine atom or a cyano group, and even more preferably a cyano group, from the viewpoint of electron controllability of the [B] electron acceptor.

  Examples of the compounds represented by the above formulas (3-1) to (3-5) include compounds represented by the following formulas.

  Among these, the quinone compound, the quinodimethane compound, and the dibenzofuran compound are considered that the electronic controllability is appropriately increased, and the lithography performance of the resist pattern to be formed is further improved. Therefore, the above formulas (3-1) to ( The compound represented by 3-4) is preferable, the compound represented by the above formula (3-3), the compound represented by the formula (3-4) is more preferable, and 2,3,5,6-tetrachloro -1,4-Benzoquinone and 7,7,8,8-tetracyanoquinodimethane are more preferred, and 7,7,8,8-tetracyanoquinodimethane is particularly preferred.

  Next, the compounds represented by the above formula (1-1) and formula (1-2) will be described.

In the above formula (1-1) and formula (1-2), R ^{1 to} R ⁵ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. Z ^- and Q ^- are each ^{independently, OH -, R A -COO -} , R A -SO 3 - or ^R A ^-N - is _-SO 2 -R ^B. R ^A is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. However, a part or all of the hydrogen atoms of R ^A may be substituted. R ^B is an alkyl group or an aralkyl group. However, some or all of the hydrogen atom of the R ^B may be substituted with a fluorine atom.

Examples of the alkyl group represented by R ^{1 to} R ⁵ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group. Groups and the like.

Examples of the alkoxy group represented by R ^{1 to} R ⁵ include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, a sec-butoxy group, and a t-butoxy group. Groups and the like.

Examples of the halogen atom represented by R ^{1 to} R ⁵ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group represented by R ^A and R ^B include groups similar to those exemplified as the alkyl groups of R ^{1 to} R ⁵ .

Examples of the cycloalkyl group represented by R ^A include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, and the like.

Examples of the aryl group represented by R ^A include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a cyclohexylphenyl group, a naphthyl group, and an anthryl group.

Examples of the aralkyl group represented by R ^A and R ^B include a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthrylmethyl group.

Examples of the substituent that R ^A may have include, for example, halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, carboxyl group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group , Alkoxycarbonyloxy group, acyl group and the like. Among these, from the viewpoint of electron acceptability of the [B] electron acceptor, a halogen atom, a hydroxyl group, a cyano group, and a nitro group are preferable, and a fluorine atom, a chlorine atom, a hydroxyl group, a cyano group, and a nitro group are more preferable. More preferred are a fluorine atom and a hydroxyl group.

  As a compound represented by Formula (1-1) and (1-2), the compound etc. which are represented by a following formula are mentioned, for example.

  Among these, the compound (sulfonium salt) represented by the above formula (1) is preferable because the electron controllability is considered to be increased moderately, and the lithography performance of the resulting resist pattern is further improved. More preferred is a sulfonium salt containing an anion having an aromatic ring to which a group is bonded, more preferred is a sulfonium salt containing an anion having a benzene ring to which a trifluoromethyl group is bonded, and triphenylsulfonium 2-hydroxy-4-trifluoromethylbenzoate. 4-cyclohexylphenyldiphenylsulfonium 2-hydroxy-4-trifluoromethylbenzoate is particularly preferred, and triphenylsulfonium 2-hydroxy-4-trifluoromethylbenzoate is more particularly preferred.

  [B] The content of the electron acceptor is usually 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 100 parts by weight of [A] polysiloxane. 1 part by mass to 10 parts by mass. [B] By setting the content of the electron acceptor in the above range, a pattern formed by using a multilayer resist process in a region finer than 50 nm can be used for pattern collapse resistance, resolution, rectangularity of the pattern shape, etc. The lithography performance can be improved.

<[C] solvent>
The silicon-containing film forming composition for a multilayer resist process usually contains a [C] solvent. [C] The solvent is not particularly limited as long as it can dissolve or disperse [A] polysiloxane, [B] electron acceptor and optional components described below.

  [C] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, and hydrocarbon solvents.

As an alcohol solvent, for example,
Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert- Pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n- Nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, furf Alcohol, phenol, cyclohexanol, methyl cyclohexanol, 3,3,5-trimethyl cyclohexanol, benzyl alcohol, mono-alcohol solvents such as diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 -Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

As an ether solvent, for example,
Dialiphatic ether solvents such as diethyl ether, dipropyl ether, dibutyl ether;
Aromatic ring ether solvents such as anisole and diphenyl ether;
Examples thereof include cyclic ether solvents such as tetrahydrofuran and dioxane.

Examples of ketone solvents include:
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-amyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone Chain ketone solvents such as trimethylnonanone and acetophenone;
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone;
And diketone solvents such as 2,4-pentanedione and acetonylacetone.

Examples of the amide solvent include
Chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide;
Examples thereof include cyclic amide solvents such as N-methylpyrrolidone and N, N′-dimethylimidazolidinone.

Examples of ester solvents include:
Methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n propionate -Butyl, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, etc. Carboxylate solvent;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether Carboxylic acid ester solvents of polyhydric alcohol partial ethers such as acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate;
Lactone solvents such as γ-butyrolactone and γ-valerolactone;
Examples thereof include carbonate solvents such as diethyl carbonate and propylene carbonate.

Examples of the hydrocarbon solvent include
Aliphatic carbonization such as n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, methylcyclohexane A hydrogen-based solvent;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbon solvents and the like.

  Among these, alcohol solvents and ester solvents are preferable, polyhydric alcohol partial ether solvents, and carboxylic acid ester solvents of polyhydric alcohol partial ethers are more preferable. Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Monomethyl ether acetate and propylene glycol monoethyl ether acetate are more preferable, and propylene glycol monoethyl ether and propylene glycol monomethyl ether acetate are particularly preferable.

<Optional component>
In addition to [A] polysiloxane and [B] electron acceptor, the silicon-containing film forming composition for a multilayer resist process further includes β-diketone, colloidal silica, colloidal alumina, organic polymer, surfactant, Arbitrary components, such as an acid generator and a nitrogen-containing compound, may contain.

<Method for preparing silicon-containing film forming composition for multilayer resist process>
The silicon-containing film forming composition for a multilayer resist process is prepared, for example, by mixing [A] polysiloxane, [B] electron acceptor, and optional components as necessary, and dissolving or dispersing in [C] solvent. be able to. As solid content concentration of the said silicon-containing film formation composition for multilayer resist processes, it is 0.5 mass%-20 mass% normally, Preferably it is 1 mass%-15 mass%, More preferably, it is 0.5 mass% -2. 0% by mass.

<Pattern formation method>
[Pattern Forming Method I]
The pattern forming method I of the present invention uses (I-1) a silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane and [B] electron acceptor, and silicon on the upper surface side of the substrate to be processed. A step of forming a containing film, (I-2) a step of forming a resist film on the silicon-containing layer using a resist composition, and (I-3) exposing the resist film by irradiation with radiation through a photomask. (I-4) developing the exposed resist film to form a resist pattern; and (I-5) sequentially etching the silicon-containing film and the substrate to be processed using the resist pattern as a mask. The process of carrying out. According to the pattern formation method I, since the silicon-containing film forming composition for a multilayer resist process described above is used, the formation of a resist pattern having excellent pattern collapse resistance, resolution, and rectangular shape of the pattern shape is performed. A good pattern can be formed on the processed substrate. Hereinafter, each step will be described.

[Step (I-1)]
In this step, a silicon-containing film is formed on the upper surface side of the substrate to be processed using a silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane and [B] electron acceptor.

As the substrate to be processed, a conventionally known substrate such as a silicon wafer or a wafer coated with aluminum can be used. On the substrate to be processed, another lower layer film (hereinafter, also referred to as “other lower layer film”) different from the silicon-containing film obtained by using the silicon-containing film forming composition for a multilayer resist process is formed in advance. It may be. The other lower layer film is a film provided with an antireflection function, coating film flatness, high etching resistance against a fluorine-based gas such as CF _{4, and the} like. Other underlayer films can be formed using, for example, commercially available products such as “NFC HM8005” (manufactured by JSR) and “NFC CT08” (manufactured by JSR). The film thickness of the other lower layer film is usually 10 nm or more and 200 nm or less, and 20 nm or more and 100 nm or less is preferable in order to improve the patternability and processing performance.

  Although it does not specifically limit as a formation method of said other lower layer film, For example, the coating film formed by apply | coating the composition which forms another lower layer film by well-known methods, such as a spin coat method, on a to-be-processed substrate Can be cured by exposure and / or heating.

  As a method for forming a silicon-containing film from the silicon-containing film forming composition for a multilayer resist process, for example, a substrate to be processed and other lower layer films (including antireflection films) formed on the substrate to be processed By applying to the surface, a coating film of the silicon-containing film forming composition for multilayer resist process is formed, and by heating the coating film, or the silicon-containing film forming composition for multilayer resist process is latent In the case of containing a photoacid generator, a method of curing by irradiating with ultraviolet light and heat treatment may be mentioned.

  Examples of the coating method include known methods such as spin coating, roll coating, and dipping.

  After the application, if necessary, the solvent in the coating film may be volatilized by pre-baking (PB). The PB temperature is appropriately selected depending on the composition of the silicon-containing film forming composition for a multilayer resist process, but is usually 50 ° C to 450 ° C, preferably 100 ° C to 300 ° C.

  The thickness of the silicon-containing film to be formed is usually 5 nm or more and 200 nm or less, and preferably 5 nm or more and 100 nm or less, more preferably 5 nm or more and 50 nm or less, in order to improve the patternability and processing performance, and 10 nm or more and 30 nm. The following is more preferable.

[Step (I-2)]
In this step, a resist composition is used to form a resist film on the silicon-containing film. Examples of the resist composition used in this step (I-2) include a positive or negative chemically amplified resist composition containing an acid generator, a positive composition comprising an alkali-soluble resin and a quinonediazide photosensitizer. And a negative resist composition comprising an alkali-soluble resin and a crosslinking agent.

  As solid content concentration of the said resist composition, it is preferable that it is 0.1-50 mass%, 0.5 mass%-30 mass% are more preferable, 1 mass%-15 mass% are further more preferable.

  As said resist composition, what was filtered using the filter with a hole diameter of about 0.2 micrometer is used suitably. In the pattern forming method of the present invention, a commercially available resist composition can be used as it is as the resist composition.

  The method for applying the resist composition is not particularly limited, and examples thereof include conventional methods such as spin coating. In addition, when apply | coating a resist composition, it is preferable to adjust the quantity of the resist composition to apply | coat so that the resist film obtained may become a predetermined film thickness.

  The said resist film can be formed by volatilizing the solvent in a coating film by carrying out prebaking (PB) etc. of the coating film formed by apply | coating the said resist composition. Although it adjusts suitably as a PB temperature according to the kind etc. of resist composition to be used, it is preferable that it is 30 to 200 degreeC, More preferably, it is 50 to 150 degreeC. In addition, you may provide another film on the surface of this resist film.

  The thickness of the resist film to be formed is usually 10 nm to 200 nm, preferably 10 nm to 100 nm, and more preferably 20 nm to 70 nm.

[Step (I-3)]
In this step, exposure is performed on the desired region of the resist film formed in step (I-2) by irradiation with radiation through a photomask having a specific pattern. Examples of the radiation include deep ultraviolet rays, extreme ultraviolet rays, electromagnetic waves such as X-rays and γ rays, charged particle beams such as electron rays and α rays. Among these, extreme ultraviolet rays, X-rays, and electron beams are preferable. Since the silicon-containing film forming composition for a multilayer resist process having the above-described properties is used, the effect is more exhibited when the radiation is extreme ultraviolet rays, X-rays and electron beams, and a good pattern is formed by the pattern forming method I. Can be formed. The exposure may be performed a plurality of times in succession. For example, the first exposure is performed on a desired area through a mask, and the second exposure is performed so as to intersect with the exposure unit that has performed the first exposure. You may perform exposure. For example, when the first exposure portion and the second exposure portion are orthogonal to each other, a perfect circular contact hole pattern is easily formed in the unexposed portion surrounded by the exposure portion. When the exposure is performed a plurality of times, the exposure may be performed using different light sources. For example, ArF excimer laser light may be used for the first exposure, EUV light may be used for the second exposure, and vice versa.

  Post exposure baking (PEB) is preferably performed after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the resist composition can proceed smoothly. As PEB temperature, it is 30 to 200 degreeC normally, and 50 to 170 degreeC is preferable.

[Step (I-4)]
In this step, the resist film exposed in step (I-3) is developed using a developer to form a resist pattern. The developer used for development can be appropriately selected according to the type of resist composition used. In the case where the resist composition is a positive chemically amplified resist composition or a positive resist composition containing an alkali-soluble resin, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, Ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, choline , 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene and the like can be used. These alkaline aqueous solutions may contain an appropriate amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol. Moreover, as a developing solution, you may use the organic-solvent developing solution which has an organic solvent as a main component.

  An appropriate amount of a surfactant can be added to the developer as necessary. As the surfactant, for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant can be used.

  As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle method) ), A method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer coating nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc.

  After the development, the resist film may be washed with a rinse solution. As the rinsing solution, water is preferable when the developer is an alkaline aqueous solution, and when the developer is an organic solvent developer, an alkane solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, etc. Is preferred. Each component of the said rinse liquid may be used independently and may use 2 or more types together.

[Step (I-5)]
In this step, the silicon-containing film and the substrate to be processed are sequentially dry-etched using the resist pattern formed in step (I-4) as a mask to form a pattern on the substrate to be processed.

The dry etching can be performed using a known dry etching apparatus. The source gas during dry etching depends on the elemental composition of the object to be etched, but includes oxygen atoms such as O ₂ , CO, and CO ₂ , inert gases such as He, N ₂ , and Ar, Cl ₂ , chlorine gas such as BCl ₄ , H ₂ , NH ₃ gas, or the like can be used. In addition, these gases can also be mixed and used.

[Pattern Forming Method II]
The pattern forming method II of the present invention includes (II-1) a step of forming a silicon-containing film on the upper surface side of a substrate to be processed using a silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane. (II-2) Step of forming a resist film on the silicon-containing film using a resist composition, (II-3) Step of exposing the resist film by irradiation with extreme ultraviolet rays or electron beams through a photomask (II-4) developing the exposed resist film to form a resist pattern; and (II-5) sequentially etching the silicon-containing film and the substrate to be processed using the resist pattern as a mask. Have According to the pattern formation method II, [A] a silicon-containing film forming composition for a multilayer resist process containing polysiloxane, and using an extreme ultraviolet ray or an electron beam as radiation, the resist pattern is formed in the multilayer resist process. Even if it is a thin film, a favorable pattern can be formed on the substrate to be processed.

[Step (II-1)]
In this step, a silicon-containing film is formed on the upper surface side of the substrate to be processed using the silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane. Examples of the substrate to be processed include those similar to the pattern forming method I described above. Examples of the method for forming the silicon-containing film include a method similar to the step (I-1) of the pattern forming method I.

[Step (II-2)]
In this step, a resist film is formed using the resist composition on the silicon-containing film formed in the step (II-1). Examples of the method for forming the resist film include the same method as in step (I-2) of the pattern forming method I.

[Step (II-3)]
In this step, the resist film formed in the above step (II-2) is exposed by irradiation with extreme ultraviolet rays or electron beams through a photomask. Examples of the exposure method include the same methods as those in the step (I-3) of the pattern formation method I except that extreme ultraviolet rays are used as radiation.

[Step (II-4)]
In this step, the resist film exposed in the above step (II-3) is developed to form a resist pattern. Examples of the developing method include the same method as in the step (I-4) of the pattern forming method I.

[Step (II-5)]
In this step, the silicon-containing film and the substrate to be processed are sequentially dry etched using the resist pattern formed in the step (II-4) as a mask. Examples of the dry etching method include a method similar to the step (I-5) of the pattern forming method I.

<Resist composition>
A preferred example of the resist composition used in the pattern forming method is a positive chemically amplified resist composition containing a radiation-sensitive acid generator. Examples of the chemically amplified resist include a polymer containing a structural unit having an acid-dissociable group (hereinafter also referred to as “polymer (I)”), a radiation-sensitive acid generator and a solvent containing a solvent. In addition, an acid diffusion control agent or the like may be contained.

[Polymer (I)]
The polymer (I) includes a structural unit having an acid dissociable group. Examples of the structural unit having an acid dissociable group include a structural unit represented by the following formula (4) (hereinafter also referred to as “structural unit (1)”), a structural unit (7) described later, and the like.

In the formula (4), R ⁸ represents a hydrogen atom, a methyl group, a fluorine atom or a trifluoromethyl group. R ⁹ is a divalent substituted or unsubstituted alicyclic hydrocarbon group. R ¹⁰ is a substituted or unsubstituted aryl group having 6 to 22 carbon atoms.

Although carbon number of the bivalent alicyclic hydrocarbon group represented by said R < ⁹ > is not specifically limited, 5-25 are preferable, More preferably, it is 5-20, More preferably, it is 5-15.

The divalent alicyclic hydrocarbon group represented by R ⁹ is preferably a group having a monocyclo structure, a bicyclo structure, a tricyclo structure, or a tetracyclo structure.

Specific examples of the divalent alicyclic hydrocarbon group represented by R ⁹ include
Examples of the group having a monocyclo structure include a cyclopentanediyl group, a cyclohexanediyl group, a cycloheptanediyl group, a cyclooctanediyl group, a cyclodecanediyl group, and a cyclododecanediyl group;
Examples of the group having a bicyclo structure include a norbornanediyl group, a decahydronaphthalenediyl group, and a cedrol group;
Examples of the group having a tricyclo structure include a tricyclodecanediyl group, an adamantanediyl group, and a noradamantanediyl group;
Examples of the group having a tetracyclo structure include a tetracyclododecanediyl group.

  Among these, a group having a monocyclo structure, a group having a bicyclo structure, and a group having a tricyclo structure are preferable, and a group having a monocyclo structure having 5 to 15 carbon atoms, a group having a bicyclo structure, and a group having a tricyclo structure are more preferable. More preferred are cyclopentanediyl group, cyclohexanediyl group, cycloheptanediyl group, cyclooctanediyl group, cyclodecandidiyl group, cyclododecandiyl group, adamantanediyl group, decahydronaphthalenediyl group, and norbornanediyl group.

  Examples of the substituent that the alicyclic hydrocarbon group may have include, for example, alkyl groups such as methyl group, ethyl group, and propyl group, halogen groups such as hydroxyl group, carboxyl group, fluorine atom, and bromine atom. Examples thereof include an alkoxy group such as an atom, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group, and an alkyloxycarbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aryl group having 6 to 22 carbon atoms represented by R ¹⁰ include groups derived from structures represented by the following formulas (x-1) to (x-3). When R ¹⁰ is a group derived from the structure represented by the following formula (x-2) (that is, a naphthyl group), the bonding positions bonded to R ⁹ in the above formula (4) are the 1-position and 2 Any of the positions may be used. In addition, when R ¹⁰ is a group derived from the structure represented by the following formula (x-3) (ie, an anthryl group), the bonding position bonded to R ⁹ in the above formula (4) is the 1st position, 2 Either the position or the 9th position may be used.

Examples of the substituent that the aryl group represented by R ¹⁰ may have include those exemplified as the substituent that the alicyclic hydrocarbon group represented by R ⁹ may have. The same group etc. are mentioned.

  In addition to the structural unit (1), the polymer (I) is represented by the structural unit represented by the following formula (5) (hereinafter, also referred to as “structural unit (2)”), and the following formula (6). Structural unit (hereinafter also referred to as “structural unit (3)”), structural unit represented by the following formula (7) (hereinafter also referred to as “structural unit (4)”), and represented by the following formula (8) It may further contain at least one of structural units (hereinafter also referred to as “structural unit (5)”). The polymer (I) may contain one or more of each of the structural units (2) to (5).

In the above formula ^{(5), R 11} is hydrogen atom or a methyl group. R ¹² is a monovalent organic group. i is an integer of 0-3. j is an integer of 0-3. When j is 2 or more, the plurality of R ¹² may be the same or different. However, 0 ≦ i + j ≦ 5 is satisfied.

In the above formula ^{(6), R 13} is a hydrogen atom or a methyl group. R ¹⁴ is a monovalent organic group. k is an integer of 0-3. m is an integer of 0-3. When m is 2 or more, the plurality of R ¹⁴ may be the same or different. However, 0 ≦ k + m ≦ 5 is satisfied.

In the above formula ^{(7), R 15} is a hydrogen atom or a methyl group. R ¹⁶ is a monovalent organic group. n is an integer of 0-3. p is an integer of 0-3. When p is 2 or more, the plurality of R ¹⁶ may be the same or different. However, 0 ≦ n + p ≦ 5 is satisfied.

In the formula ^{(8), R 17} is a hydrogen atom or a methyl group. R ¹⁸ is a monovalent organic group. q is an integer of 0-3. r is an integer of 0-3. When r is 2 or more, the plurality of R ¹⁸ may be the same or different.

Examples of the monovalent organic group represented by R ¹² , R ¹⁴ , R ¹⁶ and R ¹⁸ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and 2-methyl. A linear or branched alkyl group having 1 to 12 carbon atoms such as propyl group, 1-methylpropyl group, t-butyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n- Linear or branched alkoxy group having 1 to 12 carbon atoms such as butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group; cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl Group, cyclodecanyl group, cycloalkyl group such as cyclododecanyl group; adamantyl group, noradamantyl group, decahydronaphthyl group, tricyclodecani Group, tetracyclododecanyl group, norbornyl group, cedrol group, and the like. Among these, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are preferable.
In the above formula (5), i is preferably 1 or 2, and j is preferably an integer of 0 to 2.
In the above formula (6), k is preferably 1 or 2, and m is preferably 0 or 1.
In the above formula (7), n is preferably 1 or 2, and p is preferably 0 or 1.
In the above formula (8), q is preferably 1 or 2, and r is preferably 0 or 1.

  Examples of the structural unit (2) include structural units represented by the following formulas (5-1) to (5-4).

  Examples of the structural unit (3) include structural units represented by the following formulas (6-1) and (6-2).

  Examples of the structural unit (4) include structural units represented by the following formulas (7-1) and (7-2).

  Examples of the structural unit (5) include structural units represented by the following formulas (8-1) and (8-2).

  In addition to the structural units (1) to (5), the polymer (I) is derived from a structural unit derived from a non-acid dissociable compound (hereinafter also referred to as “structural unit (6)”), an acid dissociable compound. A structural unit (hereinafter also referred to as “structural unit (7)”). The polymer (I) may contain one or more of each of these structural units.

  Examples of the non-acid dissociable compound include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, isobornyl acrylate, tricyclodecanyl (meth) acrylate, and tetracyclodone. Examples include decenyl (meth) acrylate, a compound represented by the following formula (L-1) containing a lactone structure, a compound represented by the following formula (S-1), and the like. Among these, styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, tricyclodecanyl acrylate, a compound represented by the following formula (L-1), the following formula (S- The compound represented by 1) is preferred.

In the above formula (L-1), R ^L1 represents a hydrogen atom, a methyl group, or a trifluoromethyl group. R ^L2 is a single bond or a divalent linking group. R ^L3 is a monovalent organic group having a lactone structure.

In the above formula (S-1), R ^S1 represents a hydrogen atom, a halogen atom, a cyano group, or an optionally substituted alkyl group. R ^S2 is a hydrogen atom, a halogen atom, a cyano group, or an optionally substituted alkyl group, cycloalkyl group, alkoxyl group, acyl group, acyloxy group, alkenyl group, aryl group or aralkyl group. R ^{S3 to} R ^S8 are each independently a hydrogen atom, a fluorine atom or an optionally substituted alkyl group. R ^S9 is a hydrogen atom, an optionally substituted alkyl group, a cycloalkyl group, an acyl group, an alkylsulfonyl group or an alkoxycarbonyl group. r is an integer of 0-5. s is an integer of 1-5. However, r + s = 5 is satisfied. If R ^S2 to R ^S9 is plural, respectively, it may be different in each of a plurality of ^R S2 ^{to R S9} are the same. However, at least one of R ^{S2 to} R ^S8 is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.

Examples of the divalent linking group represented by R ^L2, for example, such as a divalent linear or branched hydrocarbon group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having a lactone structure represented by R ^L3 include groups represented by the following formulas (L3-1) to (L3-6).

In the above formulas (L3-1) to (L3-6), R ^Lc1 is an oxygen atom or a methylene group. R ^Lc2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n _Lc1 is 0 or 1. _nLc2 is an integer of 0-3. * ^Shows the site ^| part couple ^| bonded with RL2 of the said formula (L-1). In addition, the group represented by the formulas (L3-1) to (L3-6) may have a substituent.

  Examples of the compound represented by the formula (L-1) include compounds described in International Publication No. 2007/116664, paragraph [0043].

  Examples of the compound represented by the formula (S-1) include a compound represented by the following formula (S-1-1), a compound represented by the formula (S-1-2), and the like.

  Examples of the acid dissociable compound include compounds represented by the following formulas (9-1) and (9-2).

In the above formulas (9-1) and (9-2), R ¹⁹ , R ²⁰ , R ²¹ , R ²⁵ , R ²⁶ and R ²⁷ are each independently a hydrogen atom, a methyl group, a trifluoromethyl group or Hydroxymethyl group. R ²² , R ²³ , R ²⁴ , R ²⁸ , R ²⁹ and R ³⁰ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent fat having 4 to 20 carbon atoms. A cyclic hydrocarbon group or a group derived from these groups. However, any two of R ²² , R ²³ and R ²⁴ , or any two of R ²⁸ , R ²⁹ and R ³⁰ are bonded to each other, and the number of carbon atoms together with the carbon atom to which they are bonded. 4-20 divalent alicyclic hydrocarbon groups or groups derived therefrom may be formed.

A linear or branched chain having 1 to 4 carbon atoms represented by R ¹⁹ , R ²⁰ and R ^{21 of} the above formula (9-1) and R ²⁵ , R ²⁶ and R ²⁷ of the formula (9-2). Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, and a t-butyl group.

In addition, R ¹⁹ , R ²⁰ and R ²¹ in the above (9-1), and a monovalent alicyclic group having 4 to 20 carbon atoms represented by R ²⁵ , R ²⁶ and R ²⁷ in the formula (9-2). Examples of the hydrocarbon group include groups composed of alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Is mentioned.

  Examples of the group derived from the alicyclic hydrocarbon group include a part or all of hydrogen atoms of the monovalent alicyclic hydrocarbon group, for example, a methyl group, an ethyl group, an n-propyl group, i 1 or more or 1 or more types of C1-C4 linear, branched, or cyclic alkyl groups, such as -propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group Examples include groups substituted with at least one group.

  Among these, the alicyclic hydrocarbon group and the group derived therefrom include groups consisting of alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane, A group in which a group consisting of a cyclic ring is substituted with the above alkyl group is preferred.

Any two of the above R ²² , R ²³ and R ²⁴ , or any two of R ²⁸ , R ²⁹ and R ³⁰ are bonded together and formed together with the carbon atom to which they are bonded. Examples of the divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclobutanediyl group, a cyclopentanediyl group, a cyclohexanediyl group, and a cyclooctanediyl group.

Examples of the group derived from the divalent alicyclic hydrocarbon group formed above include a part or all of the hydrogen atoms of the divalent alicyclic hydrocarbon group, for example, a methyl group, an ethyl group, C1-C4 linear, branched or cyclic alkyl groups such as n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group and t-butyl group Or a group substituted with one or more of the above.
Among these, a cyclopentanediyl group, a cyclohexanediyl group, and a group in which these groups are substituted with the alkyl group are preferable.

  As the structural unit (7), structural units represented by the following formulas (9-1-1) to (9-1-7) and (9-2-1) are preferable.

In the above formulas (9-1-1) to (9-1-7) and (9-2-1), R ²¹ and R ²⁷ each independently represent a hydrogen atom, a methyl group, a trifluoromethyl group or Hydroxymethyl group. R ^{22 to} R ²⁴ and R ^{28 to} R ³⁰ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms.

The content ratio of the structural unit (1) in the polymer (I) is 5 mol% to 70 mol%, preferably 5 mol% to 50 mol%, based on all structural units constituting the polymer (I). It is. When this content ratio is in the above range, the resist composition can be excellent in nano edge roughness.
The total content of the structural units (2) to (5) is preferably 1 mol% or more, more preferably 5 mol% to 95 mol%, based on all structural units constituting the polymer (I). More preferably, it is 5 mol% to 80 mol%. If the total content exceeds 95 mol%, the nano edge roughness of the resist composition may deteriorate.
The total content of the structural units (1) to (5) is preferably 10 mol% or more, more preferably 40 mol% to 100 mol%, based on all structural units constituting the polymer (I). More preferably, it is 50 mol% to 100 mol%. By setting the total content to 10 mol% or more, the resist composition can be made excellent in nano edge roughness.

As a content rate of the said structural unit (6), it is 80 mol% or less normally with respect to all the structural units which comprise polymer (I), Preferably it is 0 mol%-60 mol%, More preferably 5 mol% to 30 mol%. By setting the content ratio to 80 mol% or less, the resist composition can be excellent in performance balance between resolution performance and nanoedge roughness.
As a content rate of the said structural unit (7), it is 60 mol% or less normally with respect to all the structural units which comprise polymer (I), Preferably it is 0 mol%-50 mol%, More preferably It is 20 mol%-50 mol%. By setting the content ratio to 60 mol% or less, the resist composition can be excellent in performance balance between resolution performance and nanoedge roughness.
The total content of the structural units (6) and (7) is usually 90 mol% or less, preferably 0 mol% to 80 mol, with respect to all structural units constituting the polymer (I). %, More preferably 20 mol% to 70 mol%. By setting the content ratio to 90 mol% or less, the resist composition can be excellent in performance balance between resolution performance and nanoedge roughness.

  Although it does not specifically limit as a synthesis method of polymer (I), For example, the method by well-known radical polymerization or anion polymerization etc. are mentioned.

  The polystyrene-converted weight average molecular weight (hereinafter also referred to as “Mw”) measured by gel permeation chromatography (GPC) of the polymer (I) is preferably 1,500 to 100,000, more preferably 1,500. It is -40,000, More preferably, it is 2,000-25,000, Most preferably, it is 5,000-15,000.

  The ratio (Mw / Mn) between the Mw of the polymer (I) and the polystyrene-equivalent number average molecular weight (hereinafter also referred to as “Mn”) measured by GPC is usually 1 to 5, more preferably 1 to 4. More preferably, it is 1-3.

[Radiosensitive acid generator]
A radiation-sensitive acid generator (hereinafter also referred to as “acid generator (P)”) generates an acid within the resist film when the resist film formed of the resist composition is irradiated with radiation or the like in a lithography process. It is a generated substance. The acid dissociable group in the polymer (I) is dissociated by the action of the acid generated from the acid generator (P).

  The acid generator (P) is preferably at least one selected from the group consisting of an onium salt, a diazomethane compound and an N-sulfonyloxyimide compound from the viewpoint of good acid generation efficiency, heat resistance and the like. The acid generator (P) may be used alone or in combination of two or more.

As said onium salt, the compound represented by a following formula (b1) is preferable.
M ⁺ L ⁻ (b1)
In the formula (b1), M ⁺ is a monovalent onium cation. L ⁻ is a monovalent anion.

  Examples of the onium salt include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Among these, from the viewpoint of obtaining better sensitivity, an onium cation (sulfonium cation) containing a sulfur atom and an onium cation (iodonium cation) containing an iodine atom are preferable.

Examples of the monovalent onium cation represented by M ⁺ in the formula (b1) include a cation represented by the following formula (b1-M-1) and the following formula (b1-M-2). And cations.

In said formula (b1-M-1), R <^31> , R ^<32> and R ^<33> are each independently the C1-C10 linear or branched alkyl group which may be substituted, or substitution Or an aryl group having 6 to 18 carbon atoms. However, any two of R ³¹ , R ³² and R ³³ are bonded to each other to form a cyclic structure together with the sulfur atom to which these are bonded, and the remaining one may be substituted. Or a linear or branched alkyl group or an optionally substituted aryl group having 6 to 18 carbon atoms.

In the above formula (b1-M-2), R ³⁴ and R ³⁵ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms which may be substituted, or substituted. Or an aryl group having 6 to 18 carbon atoms. However, R ³⁴ and R ³⁵ may be bonded to each other to form a cyclic structure together with the iodine atom to which they are bonded.

Examples of the unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms in the above formulas (b1-M-1) and (b1-M-2) include, for example, a methyl group, an ethyl group, and n- A propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned.
Examples of the substituent which this alkyl group may have include, for example, a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, And organic groups containing a sulfur atom, phosphorus atom, silicon atom, etc.).

Examples of the unsubstituted aryl group having 6 to 18 carbon atoms in the above formulas (b1-M-1) and (b1-M-2) include a phenyl group and a naphthyl group.
Examples of the substituent that the aryl group may have include, for example, a halogen atom such as fluorine, chlorine, bromine, and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, A nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, etc.).

  The monovalent onium cation represented by M + is preferably a sulfonium cation, more preferably a triarylsulfonium cation, and still more preferably a triphenylsulfonium cation.

The monovalent onium cation moiety represented by M ⁺ in the formula (b1) is described in, for example, Advances in Polymer Sciences, Vol. 62, p. It can be synthesized according to a known method described in 1-48 (1984).

Examples of the monovalent anion represented by L ⁻ in the formula (b1) include anions represented by the following formulas (b1-L-1) to (b1-L-4). Among these, anions represented by the following formula (b1-L-1) or (b1-L-2) are preferable.

In the above formula (b1-L-1), R ³⁶ and R ³⁷ are each independently a fluorine atom or an alkyl group having 1 to 20 carbon atoms having at least one fluorine atom. However, R ³⁶ and R ³⁷ may be bonded to each other to form a C 1-20 cyclic structure having at least one fluorine atom.
In the formula (b1-L-2), R ³⁸ , R ³⁹ and R ⁴⁰ are each independently an alkyl group having 1 to 20 carbon atoms having at least one fluorine atom. However, any two of R ³⁸ , R ³⁹ and R ⁴⁰ are bonded to each other to form a C 1-20 cyclic structure having at least one fluorine atom, and the remaining one is at least one. The C1-C20 alkyl group which has the following fluorine atom may be sufficient.
In the formula (b1-L-3) and the formula (b1-L-4), R ⁴¹ and R ⁴² are each independently a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms. It is. n is an integer of 1-10.

  Examples of the alkyl group having 1 to 20 carbon atoms having at least one fluorine atom in the above formulas (b1-L-1) and (b1-L-2) include, for example, a methyl group, an ethyl group, an n-propyl group, Examples include a group in which at least one hydrogen atom of an alkyl group such as i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like is substituted with a fluorine atom.

Specific examples of the onium salt include, for example, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfoniumbenzenesulfonate, triphenylsulfonium-10-camphorsulfonate, triphenylsulfonium n-octanesulfonate. , Triphenylsulfonium 4-trifluoromethylbenzenesulfonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium perfluorobenzenesulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0 .1 ^2,5 .1 ^7,10 ] dodecan-8-yl) ethanesulfonate, triphenylsulfonium 1,1-di Fluoro-2- (bicyclo [2.2.1] heptan-2-yl) ethanesulfonate, triphenylsulfonium 1,2-bis (cyclohexyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2-bis ( Norbornyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2-bis (tetrahydropyranyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2-bis (2-heptyloxycarbonyl) ethane- 1-sulfonate;
(4-t-butoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium perfluoro-n-octanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium-10-camphorsulfonate, (4-hydroxyphenyl) diphenylsulfonium trifluoromethanesulfonate, (4-hydroxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-hydroxyphenyl) Diphenylsulfonium perfluoro-n-octanesulfonate, (4-hydroxyphenyl) diphenylsulfonium-10-camphorsulfur Sulfonate, (4-hydroxyphenyl) diphenyl sulfonium -n- octane sulfonate,
Tris (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-methoxyphenyl) sulfonium nonafluoro-n-butanesulfonate, tris (4-methoxyphenyl) sulfonium perfluoro-n-octanesulfonate, tris (4-methoxyphenyl) ) Sulfonium-10-camphorsulfonate, (4-fluorophenyl) diphenylsulfonium trifluoromethanesulfonate, (4-fluorophenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) diphenylsulfonium-10-camphorsulfonate; Tris (4-fluorophenyl) sulfonium trifluoromethanesulfonate, tris (4-fluorophenyl) sulfonium Nafluoro-n-butanesulfonate, tris (4-fluorophenyl) sulfonium-10-camphor sulfonate, tris (4-fluorophenyl) sulfonium-p-toluenesulfonate, tris (4-trifluoromethylphenyl) sulfonium trifluoromethanesulfonate ;
2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium-2,4-difluorobenzenesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium-4-trifluoromethylbenzene Sulfonate; diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium-10-camphorsulfonate, diphenyliodonium-n-octanesulfonate,
Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-t-butylphenyl) iodonium-10-camphorsulfonate, bis (4-t-butylphenyl) iodonium-n-octanesulfonate, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, (4-methoxyphenyl) Phenyliodonium nonafluoro-n-butanesulfonate, (4-methoxyphenyl) phenyliodonium perfluoro-n-octanesulfonate,
(4-fluorophenyl) phenyliodonium trifluoromethanesulfonate, (4-fluorophenyl) phenyliodonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) phenyliodonium 10-camphorsulfonate; bis (4-fluorophenyl) iodonium trifluoro Lomethanesulfonate, bis (4-fluorophenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-fluorophenyl) iodonium 10-camphorsulfonate;
Bis (4-chlorophenyl) iodonium trifluoromethanesulfonate, bis (4-chlorophenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-chlorophenyl) iodonium perfluoro-n-octanesulfonate, bis (4-chlorophenyl) iodonium n- Dodecylbenzenesulfonate, bis (4-chlorophenyl) iodonium-10-camphorsulfonate, bis (4-chlorophenyl) iodonium-n-octanesulfonate, bis (4-chlorophenyl) iodonium-4-trifluoromethylbenzenesulfonate, bis (4- Chlorophenyl) iodonium perfluorobenzenesulfonate;
Bis (4-trifluoromethylphenyl) iodonium trifluoromethanesulfonate, bis (4-trifluoromethylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-trifluoromethylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-trifluoromethylphenyl) iodonium-n-dodecylbenzenesulfonate, bis (4-trifluoromethylphenyl) iodonium-p-toluenesulfonate, bis (4-trifluoromethylphenyl) iodoniumbenzenesulfonate, bis (4- Trifluoromethylphenyl) iodonium-10-camphorsulfonate, bis (4-trifluoromethylphenyl) iodonium-n-octanesulfonate, bis (4- Trifluoromethyl phenyl) iodonium 4-trifluoromethyl benzenesulfonate, bis (4-trifluoromethylphenyl) iodonium perfluoro sulfonate;
Examples include compounds represented by the following formulas (2x-1) to (2x-43).

Among these onium salts, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium 1,2-bis (cyclohexyloxycarbonyl) ethane-1- Sulfonate, triphenylsulfonium 1,2-bis (norbornyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2-bis (tetrahydropyranyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2 -Bis (2-heptyloxycarbonyl) ethane-1-sulfonate, (4-hydroxyphenyl) diphenylsulfonium trifluoromethanesulfonate, 4-hydroxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, tris (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-methoxyphenyl) sulfonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) diphenyl Sulfonium trifluoromethanesulfonate, (4-fluorophenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium-2,4- Difluorobenzenesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium-4-trifluoromethylbenzenes Honeto,
Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium-10-camphorsulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro -N-butanesulfonate, bis (4-t-butylphenyl) iodonium-10-camphorsulfonate, (4-fluorophenyl) phenyliodonium trifluoromethanesulfonate, (4-fluorophenyl) phenyliodonium nonafluoro-n-butanesulfonate, (4-Fluorophenyl) phenyliodonium-10-camphorsulfonate, bis (4-fluorophenyl) iodoni Mutrifluoromethanesulfonate, bis (4-fluorophenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-fluorophenyl) iodonium-10-camphorsulfonate, tris (4-trifluoromethylphenyl) sulfonium trifluoromethanesulfonate, tri triphenylsulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecane-8-yl) ethanesulfonate, triphenylsulfonium 1,1 -Difluoro-2- (bicyclo [2.2.1] heptan-2-yl) ethanesulfonate; the above formulas (2x-13), (2x-16), (2x-17), (2x-18), ( 2x-19), (2x-20), (2x-27), (2x-28) , (2x-29), (2x-31), (2x-36), and (2x-43) are preferred, and triphenylsulfonium 1,2-bis (cyclohexyloxycarbonyl) ethane-1-sulfonate , Triphenylsulfonium 1,2-bis (norbornyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2-bis (tetrahydropyranyloxycarbonyl) ethane-1-sulfonate, triphenylsulfonium 1,2- Bis (2-heptyloxycarbonyl) ethane-1-sulfonate is more preferred.

Examples of the diazomethane compound include bis (trifluoromethanesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecane-8-sulfonyl) diazomethane, and bis. (1,4-dioxaspiro [4.5] decane-7-sulfonyl) diazomethane, bis (t-butylsulfonyl) diazomethane and the like.
Among these diazomethane compounds, bis (cyclohexylsulfonyl) diazomethane, bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecane-8-sulfonyl) diazomethane, bis (1,4-dioxaspiro [4. 5] Decane-7-sulfonyl) diazomethane is preferred.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyl). Oxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6 -Oxy-2,3-dicarboximide; N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2. 2.1] Hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyl) Xyl) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide, N-[(5-methyl-5-carboxymethyl) Bicyclo [2.2.1] heptan-2-yl) sulfonyloxy] succinimide;
N- (n-octylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (n-octylsulfonyloxy) bicyclo [2.2.1] heptane- 5,6-oxy-2,3-dicarboximide, N- (perfluorophenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro Phenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5 , 6-oxy-2,3-dicarboximide, N- (nonafluoro-n-butylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3 Dicarboximide, N- (nonafluoro-n-butylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butylsulfonyl) Oxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide;
N- (perfluoro-n-octylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octylsulfonyloxy) -7-oxa Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy- 2,3-dicarboximide etc. are mentioned.

  Among these N-sulfonyloxyimide compounds, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) ) Succinimide, N-[(5-methyl-5-carboxymethylbicyclo [2.2.1] heptan-2-yl) sulfonyloxy] succinimide is preferred.

  As content of an acid generator (P), 0.1 mass part-50 mass parts are preferable with respect to 100 mass parts of polymers (I), More preferably, it is 0.5 mass part-50 mass parts. . There exists a possibility that a sensitivity and developability may fall that content of this acid generator (P) is less than 0.1 mass part. On the other hand, when the content exceeds 50 parts by mass, the transparency to radiation, pattern shape, heat resistance, and the like may be reduced.

[Acid diffusion control agent]
The resist composition preferably further contains an acid diffusion control agent (hereinafter also referred to as acid diffusion control agent (Q)) in addition to the polymer (I) and the acid generator. The acid diffusion control agent (Q) is a component that controls the diffusion phenomenon of the acid generated from the acid generator (P) and the like in the resist film by exposure and suppresses an undesirable chemical reaction in the unexposed area.

Examples of the acid diffusion controller (Q) include nitrogen-containing organic compounds and photosensitive basic compounds.
Examples of the nitrogen-containing organic compound include a compound represented by the following formula (Q1) (hereinafter, also referred to as “nitrogen-containing compound (i)”), a compound having two nitrogen atoms in the same molecule (hereinafter, “ A nitrogen-containing compound (ii) "), a polyamino compound or polymer having 3 or more nitrogen atoms (hereinafter collectively referred to as" nitrogen-containing compound (iii) "), an amide group-containing compound, a urea compound, And nitrogen-containing heterocyclic compounds.

In the above formula (Q1), R ⁴³ , R ⁴⁴ and R ⁴⁵ each independently represent a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, or an optionally substituted aryl. A group or an optionally substituted aralkyl group.

  Examples of the nitrogen-containing compound (i) include mono- (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; -Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Of di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octyl Amine, tri-n-nonylamine, tri-n-decylamine, cyclohexane Tri (cyclo) alkylamines such as sildimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3 -Methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N-phenyldiethanolamine, 2,6-diisopropylaniline Aromatic amines and the like.

  Examples of the nitrogen-containing compound (ii) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diamino. Diphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-amino Phenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl Ethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like.

  Examples of the nitrogen-containing compound (iii) include polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, and the like.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, and Nt. -Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)- (-)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxy Piperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbo Rupiperazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′- Diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′-di-t-butoxycarbonyl-1 , 7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di- t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenyl In addition to Nt-butoxycarbonyl group-containing amino compounds such as benzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, Examples include pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, and isocyanuric acid tris (2-hydroxyethyl).

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butyl. Examples include thiourea.

  Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2. -Imidazoles such as methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenyl Pyridines such as pyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2- Piperazines such as (hydroxyethyl) piperazine Pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, Examples include 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

  The photosensitive basic compound is a component that decomposes in the exposed area and loses basicity, and remains in the unexposed area without being decomposed. Since such a photosensitive basic compound can effectively utilize an acid generated in an exposed portion (exposed region), compared to a non-photosensitive basic compound, sensitivity can be further improved.

  The photosensitive basic compound is not particularly limited as long as it has the above properties. Specific examples include compounds represented by the following formula (Q2-1) or formula (Q2-2).

In the above formula (Q2-1) and formula (Q2-2), R ^{46 to} R ⁵⁰ are each independently a hydrogen atom, a halogen atom, or a C 1-10 alkyl group that may have a substituent. , An optionally substituted alicyclic hydrocarbon group, —OSO ₂ —R ^c group, or —SO ₂ —R ^d group. R ^c and R ^d each independently have an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, or a substituent. It is a good aryl group. E ^- it ^is, OH ^{-, R 51} O -, or ^R 51 COO ^- is. R ⁵¹ is a monovalent organic group.

R ^{46 to} R ⁴⁸ in the above formula (Q2-1) may all be the same, or some or all may be different from each other. R ⁴⁹ and R ⁵⁰ in the above formula (Q2-2) may be the same or different.

Examples of the alkyl group having 1 to 10 carbon atoms represented by R ^{46 to} R ⁵⁰ and R ^c and R ^d include a methyl group, an ethyl group, an n-butyl group, a tert-butyl group, and a trifluoromethyl group. Is mentioned. Examples of the substituent for substituting the alkyl group include a hydroxyl group, a carboxyl group, a halogen atom such as a fluorine atom and a bromine atom, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a t-butoxy group, Examples thereof include alkyloxycarbonyl groups such as t-butoxycarbonylmethyloxy group.

Examples of the alicyclic hydrocarbon group represented by R ^{46 to} R ⁵⁰ and R ^c and R ^d include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclodecyl group, a norbornyl group, Examples thereof include an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group, and the like. Examples of the substituent for substituting the alicyclic hydrocarbon group include the same groups as those exemplified as the substituent for the alkyl group having 1 to 10 carbon atoms represented by R ^{46 to} R ^50. .

The halogen atom represented by R ⁴⁶ to R ^50, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the aryl group represented by R ^c and R ^d include phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, methylnaphthyl group, dimethylnaphthyl group, anthryl group, methylanthryl group, dimethylan. And a tolyl group. Examples of the substituent for substituting the aryl group include the same groups as those exemplified as the substituent for the alkyl group having 1 to 10 carbon atoms represented by R ^{46 to} R ⁵⁰ .

Among these, R ^{46 to} R ⁵⁰ are preferably a hydrogen atom or a t-butyl group.

Among these, R ^c and R ^d are preferably a cyclohexyl group, a phenyl group, a methyl group, or a trifluoromethyl group.

Examples of the monovalent organic group represented by R ⁵¹ include an alkyl group which may have a substituent and an aryl group which may have a substituent.

The L ^{- _The,} OH ^-, CH 3 COO - and anion is preferably represented by the following formula (Q2-a1) ~ (Q2 -a5).

Specific examples of the photosensitive basic compound include, for example, a triphenylsulfonium compound (a compound represented by the above formula (Q2-1)), and an anion portion (E ⁻ ) thereof is OH ⁻ , CH ₃ COO. ^- , And an anion represented by the above formula (Q2-1) or (Q2-3).

  The content of the acid diffusion controller (Q) is preferably 30 parts by mass or less, more preferably 0.001 parts by mass to 30 parts by mass, and still more preferably 0.001 parts by mass with respect to 100 parts by mass of the polymer (I). 005 parts by mass to 15 parts by mass. When the content of the acid diffusion controller (Q) exceeds 30 parts by mass, the sensitivity of the formed resist film and the developability of the exposed part may be deteriorated. On the other hand, when the content is less than 0.001 part by mass, depending on the process conditions, there is a possibility that the goodness of the pattern shape and the dimensional fidelity of the resist pattern to be formed are lowered. The acid diffusion controller (Q) may be used alone or in combination of two or more.

[solvent]
The resist composition usually contains a solvent (hereinafter also referred to as “solvent (R)”). The solvent is not particularly limited as long as it can dissolve or disperse the polymer (I), the acid generator (P), the acid diffusion controller (Q), and other components described later. As this solvent (R), the solvent similar to what was illustrated as a [C] solvent in the said silicon-containing film formation composition for multilayer resist processes, etc. are mentioned, for example.

  The solvent (R) is preferably an ester solvent or a ketone solvent, a carboxylic acid ester solvent, a carboxylic acid ester solvent of a polyhydric alcohol partial ether, a lactone solvent, a chain ketone solvent, or a cyclic ketone solvent. More preferred are carboxylic acid ester solvents and carboxylic acid ester solvents of polyhydric alcohol partial ethers, propylene glycol monoalkyl ether acetates and lactic acid esters are particularly preferred, and propylene glycol monomethyl ether acetate and ethyl lactate are even more particularly preferred. .

[Other ingredients]
The resist composition may further contain a surfactant, a sensitizer, an aliphatic additive, and the like as other components as necessary.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Further, in this embodiment, there are those using EB (electron beam) for exposure of the resist film, but even when using short wavelength radiation such as EUV, the basic resist characteristics are similar, It is also known that they are correlated. Various physical property values were measured according to the following methods.

[Mw and Mn]
Mw and Mn of the polymer were measured under the following conditions using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL).
Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran (Wako Pure Chemical Industries)
Flow rate: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ ¹ H-NMR analysis and ¹³ C-NMR analysis]
The structural analysis of the polymer was performed by ¹ H-NMR analysis and ¹³ C-NMR analysis using a nuclear magnetic resonance apparatus (JNM-EX270, manufactured by JEOL Ltd.).

[Solid concentration of polysiloxane]
The mass was measured before and after 0.5 g of the polysiloxane solution was baked at 250 ° C. for 30 minutes, and the solid content concentration (mass%) of the polysiloxane solution was determined from the measured value.

<[A] Synthesis of polysiloxane>
[Synthesis Example 1] (Synthesis of polysiloxane (A-1))
1.28 g of oxalic acid was dissolved in 12.85 g of water by heating to prepare an aqueous oxalic acid solution. Thereafter, a cooling tube and a dropping funnel containing the oxalic acid aqueous solution prepared above were set in a flask containing 25.05 g of tetramethoxysilane, 3.63 g of phenyltrimethoxysilane and 57.19 g of propylene glycol monoethyl ether. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 97.3 g of a solution containing polysiloxane (A-1). The solid content concentration in the solution containing the obtained polysiloxane (A-1) was 18.0% by mass. Moreover, Mw of the obtained polysiloxane (A-1) was 2,000.

<Preparation of silicon-containing film forming composition for multilayer resist process>
The [B] electron acceptor and the [C] solvent used in the preparation of the silicon-containing film forming composition for the multilayer resist process are shown below.

[[B] electron acceptor]
B-1: 7,7,8,8-tetracyanoquinodimethane B-2: triphenylsulfonium 2-hydroxy-4-trifluoromethylbenzoate (compound represented by the following compound (B-2))

ｂ−１：Ｎ−ｔ−アミロキシカルボニル−４−ヒドロキシピペリジン
ｂ−２：Ｎ−ｔ−ブトキシカルボニル−４−ヒドロキシピペリジン
なお、化合物（ｂ−１）及び（ｂ−２）は、電子を受容する機能を有しない物質である。

b-1: Nt-amyloxycarbonyl-4-hydroxypiperidine b-2: Nt-butoxycarbonyl-4-hydroxypiperidine Compounds (b-1) and (b-2) accept electrons. It is a substance that does not have a function to perform.

[[C] solvent]
C-1: Propylene glycol monomethyl ether acetate C-2: Propylene glycol monoethyl ether

[Example 1] (Preparation of silicon-containing film-forming composition (S-1) for multilayer resist process)
4.76 g of the solution containing (A-1) as [A] polysiloxane obtained in Synthesis Example 1 above, 0.043 g of (B-1) as [B] electron acceptor and [C] as solvent (C-1) 29.23 g and (C-2) 69.37 g were mixed to prepare a silicon-containing film forming composition (S-1) for a multilayer resist process.

[Examples 2 to 4 and Comparative Examples 1 to 3] (Preparation of silicon-containing film forming compositions (S-2) to (S-7) for multilayer resist processes)
Silicon-containing film forming compositions (S-2) to (S-7) for multilayer resist processes were prepared in the same manner as in Example 1 except that the types and amounts of each component shown in Table 1 were used.

<Synthesis of polymer (I)>
[Synthesis Example 2] (Synthesis of Polymer (IA))
4.5 g (35 mol%) of a monomer represented by the following formula (M-1), 5.5 g (65 mol%) of p-acetoxystyrene, 2,2′-azobis (isobutyronitrile) (AIBN) ) 0.4 g and 0.1 g of t-dodecyl mercaptan were dissolved in 10 g of propylene glycol monomethyl ether, and then the polymerization was carried out for 16 hours while maintaining the reaction vessel at 70 ° C. with stirring in a nitrogen atmosphere. After the polymerization, the polymerization reaction solution was dropped into 500 g of n-hexane to coagulate and purify the resulting polymer. Next, after the obtained polymer was dissolved again in 7.5 g of propylene glycol monomethyl ether, 15 g of methanol, 4.0 g of triethylamine and 1.0 g of water were added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in 10 g of acetone and then dripped into 100 g of water to solidify. The resulting white powder was filtered and filtered under reduced pressure at 50 ° C. overnight. Drying gave a white powder of polymer (IA) (yield 68%). Mw of this polymer (IA) was 11,000, and Mw / Mn was 2.3. Moreover, as a result of ¹³ C-NMR analysis, each content ratio of the structural unit derived from the monomer (M-1) in the polymer (IA): the structural unit derived from p-hydroxystyrene was 34. 8: 65.2 (mol%).

[Synthesis Example 3] (Synthesis of Polymer (IB))
4.66 g (35 mol%) of a monomer represented by the following formula (M-2), 5.34 g (65 mol%) of p-acetoxystyrene, 0.4 g of AIBN and 0.1 g of t-dodecyl mercaptan were mixed with propylene glycol. After dissolving in 10 g of monomethyl ether, the polymerization was carried out for 16 hours while maintaining the reaction kettle with stirring in a nitrogen atmosphere at 70 ° C. After the polymerization, the polymerization reaction solution was dropped into 500 g of n-hexane to coagulate and purify the resulting polymer. Next, after the obtained polymer was dissolved again in 7.5 g of propylene glycol monomethyl ether, 15 g of methanol, 4.0 g of triethylamine and 1.0 g of water were added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in 10 g of acetone and then dripped into 100 g of water to solidify. The resulting white powder was filtered and filtered under reduced pressure at 50 ° C. overnight. It dried and the polymer (IB) of white powder was obtained (yield 74.6%). Mw of this polymer (IB) was 9,600, and Mw / Mn was 2.1. Moreover, as a result of ¹³ C-NMR analysis, each content ratio of the structural unit derived from the monomer (M-2) in the polymer (IB): the structural unit derived from p-hydroxystyrene was 35. 2: 64.8 (mol%).

[Synthesis Example 4] (Synthesis of polymer (IC))
5.29 g (30 mol%) of a monomer represented by the following formula (M-3), 2.22 g (15 mol%) of a monomer represented by the following formula (M-4) and p-acetoxystyrene 7.49 g (55 mol%), 0.83 g of AIBN and 0.3 g of t-dodecyl mercaptan were dissolved in 22.5 g of propylene glycol monomethyl ether, and the reaction vessel was kept at 70 ° C. with stirring under a nitrogen atmosphere. Polymerized for hours. After the polymerization, the polymerization reaction solution was dropped into 750 g of n-hexane to coagulate and purify the resulting polymer. Next, after the obtained polymer was dissolved again in 10.0 g of propylene glycol monomethyl ether, hydrolysis reaction was performed for 8 hours while refluxing at the boiling point by adding 20 g of methanol, 6.0 g of triethylamine and 1.5 g of water. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in 15 g of acetone, then dropped into 150 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure overnight. It dried and the polymer (IC) of white powder was obtained (yield 71.3%). Mw of this polymer (IC) was 7,800, and Mw / Mn was 2.2. Moreover, as a result of ¹³ C-NMR analysis, structural unit derived from monomer (M-3) in polymer (IC): structural unit derived from (M-4): derived from p-hydroxystyrene The respective content ratios of the structural units were 30.2: 14.8: 55.0 (mol%).

[Synthesis Example 5] (Synthesis of Polymer (ID))
6.21 g (30 mol%) of a monomer represented by the following formula (M-5), 3.99 g (15 mol%) of a monomer represented by the following formula (M-6), and p-acetoxy After dissolving 4.79 g (55 mol%) of styrene, 0.83 g of AIBN and 0.3 g of t-dodecyl mercaptan in 22.5 g of propylene glycol monomethyl ether, the reaction vessel was kept at 70 ° C. with stirring in a nitrogen atmosphere. Polymerized for 16 hours. After the polymerization, the polymerization reaction solution was dropped into 750 g of n-hexane to coagulate and purify the resulting polymer. Next, after the obtained polymer was dissolved again in 10.0 g of propylene glycol monomethyl ether, hydrolysis reaction was performed for 8 hours while refluxing at the boiling point by adding 20 g of methanol, 6.0 g of triethylamine and 1.5 g of water. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in 15 g of acetone, then dropped into 150 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure overnight. Drying gave a white powder of polymer (ID) (yield 69.3%). Mw of this polymer (ID) was 8,100, and Mw / Mn was 2.2. As a result of ¹³ C-NMR analysis, structural unit derived from monomer (M-5) in polymer (ID): structural unit derived from (M-6): derived from p-hydroxystyrene The content ratio of the structural units was 39.8: 20.4: 39.8 (mol%).

<Preparation of resist composition>
The acid generator (P), acid diffusion controller (Q) and solvent (R) used for preparing the resist composition are shown below.

[Acid generator (P)]
P-1: Triphenylsulfonium 1,2-bis (cyclohexyloxycarbonyl) ethane-1-sulfonate (compound represented by the following formula (P-1))
P-2: Triphenylsulfonium 1,2-bis (norbornyloxycarbonyl) ethane-1-sulfonate (compound represented by the following formula (P-2))
P-3: Triphenylsulfonium 1,2-bis (tetrahydropyranyloxycarbonyl) ethane-1-sulfonate (compound represented by the following formula (P-3))
P-4: Triphenylsulfonium 1,2-bis (2-heptyloxycarbonyl) ethane-1-sulfonate (compound represented by the following formula (P-4))

[Acid diffusion controller (Q)]
Q-1: Triphenylsulfonium 2-hydroxy-4-trifluoromethyl benzoate (compound represented by the following formula (Q-1))

[Solvent (R)]
R-1: Propylene glycol monomethyl ether acetate R-2: Ethyl lactate

[Preparation Example 1] (Preparation of resist composition (J-1))
1.60 g of (IA) as the polymer (I) obtained in Synthesis Example 2 above, 0.352 g of (P-1) as the acid generator (P), and as the acid diffusion inhibitor (Q) (Q-1) 0.0530 g and (R-1) 68.6 g and (R-2) 29.4 g as the solvent (R) were mixed. The obtained mixed liquid was filtered with a filter having a pore size of 0.45 μm to obtain a resist composition (J-1).

[Preparation Examples 2 to 8] (Preparation of resist compositions (J-2 to J-8))
Resist compositions (J-2) to (J-8) were obtained in the same manner as in Preparation Example 1, except that the types and amounts of the components shown in Table 2 below were used.

<Formation of silicon-containing film>
On the silicon wafer, the silicon-containing film forming composition for multilayer resist process obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was applied by spin coating. For spin coating, a coating / developing apparatus (CLEAN TRACK ACT8, manufactured by Tokyo Electron) was used (the same applies hereinafter unless otherwise specified). The obtained coating film was subjected to PB for 1 minute on a 220 ° C. hot plate to form a silicon-containing film. The thickness of the obtained silicon-containing film was measured with a film thickness measuring device (M-2000D, manufactured by JA Woollam) and found to be 15 nm.

<Evaluation>
The formed silicon-containing film, the prepared silicon-containing film-forming compositions for multilayer resist process (S-1) to (S-7) and the resist compositions (J-1) to (J -8), various evaluations were performed according to the following methods. The evaluation results are shown in Table 3.

[Oxygen ashing resistance]
The obtained silicon-containing film was O ₂ treated at 100 W for 120 seconds using an ashing apparatus (NA1300, manufactured by ULVAC), and the film thickness difference before and after the treatment was measured. When the difference between the two was less than 5 nm, the oxygen ashing resistance was evaluated as “A” (good), and when it was 5 nm or more, it was evaluated as “B” (bad).

[Lithography evaluation]
(Formation of resist pattern)
[Example 5]
An antireflection film-forming material (HM8006, manufactured by JSR) was spin-coated on an 8-inch silicon wafer, and then PB was performed at 250 ° C. for 60 seconds to form an antireflection film having a thickness of 100 nm. On this antireflection film, a silicon-containing film forming composition (S-1) for multilayer resist process is spin-coated, subjected to PB at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 60 seconds to obtain a film thickness. A 15 nm silicon-containing film was formed. Next, the prepared resist composition (J-1) is spin-coated on a silicon-containing film, subjected to PB at 130 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds, whereby a resist film having a thickness of 50 nm is obtained. Formed.

[Examples 6 to 14 and Comparative Examples 4 to 6]
A resist film was formed in the same manner as in Example 5 except that the silicon-containing film-forming composition for a multilayer resist process and the resist composition were those shown in Table 3 below.

[Comparative Example 7]
An organic antireflection film-forming composition (DUV42, manufactured by Nissan Chemical Industries) was spin-coated on an 8-inch silicon wafer, and then PB was performed at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 60 nm. Next, the resist composition (J-1) prepared above was spin-coated on this antireflection film, subjected to PB at 130 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds, whereby a resist having a thickness of 50 nm was obtained. A film was formed.

[Comparative Example 8]
After the hexamethyldisilazane treatment was applied to an 8-inch silicon wafer, the resist composition (J-1) prepared above was spin coated on the wafer, PB was performed at 130 ° C. for 60 seconds, and then at 23 ° C. for 30 seconds. By cooling, a resist film having a thickness of 50 nm was formed.

Each of the formed resist films was irradiated with an electron beam using an electron beam drawing apparatus (HL800D, manufactured by Hitachi, output: 50 KeV, current density: 5.0 amperes / cm ² ). After irradiation with an electron beam, PEB was performed at 110 ° C. for 60 seconds, followed by cooling at 23 ° C. for 60 seconds, development using a 2.38 mass% TMAH aqueous solution at 23 ° C. for 60 seconds, The resist pattern was formed by rinsing with water and drying. The resist pattern thus formed was evaluated by the following method. The evaluation results are shown in Table 3.

(Evaluation)
[sensitivity]
The exposure amount is changed by the electron beam drawing apparatus, a 100 nm line and space pattern is drawn, and a scanning electron microscope for semiconductors (high resolution FEB length measuring device S-9380, manufactured by Hitachi, Ltd.) is used. The groove width (space width) was measured. Sensitivity (μC / cm ² ) was defined as the optimum exposure amount for forming a 1: 1 line and space having a space width of 90 nm between a line having a line width of 90 nm and a line adjacent to the line with a 1: 1 line width.

[Minimum collapse dimension]
The exposure amount was varied with the electron beam drawing apparatus, a 90 nm line and space pattern was drawn, and the width of the groove (space width) between the lines was measured using the semiconductor scanning electron microscope. As the exposure amount increases, the space width increases and eventually the pattern collapses. The space width at the maximum exposure amount at which this resist pattern collapse was not confirmed was defined as the minimum dimension before collapse (nm). The greater the minimum collapse dimension value, the better the pattern collapse resistance.

[resolution]
In the 1: 1 line and space pattern, the minimum line width of the line pattern resolved at the optimum exposure amount was defined as the resolution.

[Rectangularity of pattern shape]
The cross-sectional shape of the 90 nm line-and-space pattern of the resist film obtained by the above “sensitivity” evaluation was observed with a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies), and the lower layer of the resist pattern shown in FIG. The line width Lb at the part and the line width Lu at the upper layer part of the resist pattern were measured. The rectangularity of the pattern shape is “A” (good) when the value calculated by Lu / Lb in the cross-sectional shape is 0.8 ≦ Lu / Lb ≦ 1.2, and when the value is outside this range. It was evaluated as “B” (bad).

[Example 15]
Using a coating / developing device (CLEAN TRACK ACT12, manufactured by Tokyo Electron) on a 300-inch oxide-coated 12-inch silicon wafer, spin-coating an antireflection film-forming material (HM8006, manufactured by JSR), and then at 250 ° C. for 60 seconds. By performing PB, an antireflection film having a thickness of 100 nm was formed. On this antireflection film, a silicon-containing film forming composition (S-5) for a multilayer resist process is spin-coated, subjected to PB at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 60 seconds to obtain a film thickness. A 15 nm silicon-containing film was formed. Next, the resist composition (J-1) prepared above was spin-coated on this silicon-containing film, subjected to PB at 130 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds. A film was formed. Next, the resist film was exposed through the mask pattern using an EUV exposure apparatus (SFET, manufactured by Canon, illumination condition; NA 0.30 sigma 0.70 / 0.30). Thereafter, the exposed resist film was subjected to PEB at 110 ° C. for 60 seconds, then cooled at 23 ° C. for 60 seconds, and then developed using a 2.38 mass% TMAH aqueous solution at 23 ° C. for 60 seconds by the paddle method. The obtained pattern was rinsed with pure water and dried to obtain a resist pattern. The resist pattern thus formed was evaluated according to the following method. The results are shown in Table 4.

(Evaluation)
[Minimum collapse dimension]
The measurement was performed by the same method as the minimum collapse dimension in the resist pattern formation by the electron beam exposure. At this time, the exposure amount (mJ / cm ² ) when forming a resist pattern of L / S = 1/1 having a line width of 40 nm was taken as the optimum exposure amount, and this optimum exposure amount was taken as the sensitivity. A scanning electron microscope (CG-4100, manufactured by Hitachi High-Technologies) was used to measure the line width and the distance between the lines.

[resolution]
In the line and space pattern of L / S = 1/1, the minimum line width of the line pattern resolved with the optimum exposure amount was defined as the resolution.

[Processing performance evaluation]
Using the 40 nm line and space pattern of the resist film obtained in the evaluation of the “minimum collapse dimension” as a mask, the processing performance was evaluated using an etching apparatus (Telius SCCM, manufactured by Tokyo Electron). First, the silicon-containing film was processed with CF ₄ gas. Using the processed silicon-containing film as a mask, the lower layer film was processed with O ₂ / N ₂ gas. Further, the substrate with the oxide film was processed using CHF ₃ / Ar / O ₂ gas with the processed lower layer film as a mask. When the oxide film was processed in a depth direction of 50 nm or more, the lower layer film, which is a mask for the oxide film processing, did not bend or twist.

  From the results of Table 3, when the silicon-containing film was formed using the silicon-containing film forming composition for multilayer resist process of the example, the comparative example was maintained while maintaining the high oxygen ashing resistance of the silicon-containing film. It was found that compared to the case of using the resist pattern, the resist pattern to be formed has excellent pattern collapse resistance, resolution, and rectangular pattern shape. In addition, according to the silicon-containing film forming composition for multilayer resist process of the example and the pattern forming method using the same, compared to the case of forming through a conventional organic antireflection film or directly on the substrate, It was shown that the formed resist pattern is excellent in the rectangularity and resolution of the pattern shape. The results of Table 4 also showed that the silicon-containing film forming composition for multilayer resist processes of the examples can be excellent in workability of the silicon-containing film and the substrate.

  According to the silicon-containing film forming composition for multilayer resist process and the pattern forming method of the present invention, it is possible to form a resist pattern excellent in pattern collapse resistance, resolution, and rectangularity of the pattern shape. Accordingly, a good pattern can be formed on the substrate to be processed while exhibiting excellent processing performance. Therefore, the present invention can be suitably used for a semiconductor device manufacturing process and the like that will be increasingly miniaturized in the future, and can also be suitably used particularly in a multilayer resist process in a region finer than 50 nm.

DESCRIPTION OF SYMBOLS 1 Resist pattern 2 Silicon-containing film | membrane 3 Processed substrate Lu Line width Lb in the upper layer part of resist pattern Line width in the lower layer part of a resist pattern

Claims (5)

[A] polysiloxane, and [B] an electron acceptor ,
[B] A silicon-containing film-forming composition for a multilayer resist process , wherein the electron acceptor is at least one compound selected from the group consisting of a quinone compound, a quinodimethane compound and a dibenzofuran compound . [A] The silicon-containing film forming composition for a multilayer resist process according to claim 1 , wherein the polysiloxane is a hydrolysis condensate of a compound containing a silane compound represented by the following formula (2).

(In formula (2), R ⁶ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, a cyano group, a cyanoalkyl group, an alkylcarbonyloxy group, an alkenyl group, an aryl group, or an aralkyl group. The alkyl group may be substituted with a fluorine atom, the aryl group and the aralkyl group may be substituted, X is a halogen atom or —OR ^7. R ⁷ is a monovalent organic group. a is 0-3 is an integer of. However, when a plurality of R ⁶ and X are each the plurality of R ⁶ and X may be the same or different and each represent.)   The composition for forming a silicon-containing film for a multilayer resist process according to claim 1 or 2, which is used for exposure to extreme ultraviolet rays, X-rays or electron beams. (I-1) A step of forming a silicon-containing film on the upper surface side of a substrate to be processed using a silicon-containing film forming composition for a multilayer resist process containing [A] polysiloxane and [B] an electron acceptor,
(I-2) a step of forming a resist film on the silicon-containing film using a resist composition;
(I-3) a step of exposing the resist film by irradiation with radiation through a photomask;
(I-4) developing the exposed resist film to form a resist pattern, and (I-5) sequentially etching the silicon-containing film and the substrate to be processed using the resist pattern as a mask. Yes, and
[B] The pattern forming method, wherein the electron acceptor is at least one compound selected from the group consisting of a quinone compound, a quinodimethane compound, and a dibenzofuran compound . The pattern formation method according to claim 4 , wherein the radiation in the step (I-3) is extreme ultraviolet rays, X-rays or electron beams.

Images